Web folding apparatus



June 29, 1965 1'. RAMAIKA WEB FOLDING APPARATUS 2 Sheets-Sheet 1 Filed Feb. 6. 1963 June 29,1965 1-. RAMAIKA WEB FOLDING APPARATUS 2 Sheets-Sheet 2 Filed Feb. 6, 1963 United States Patent lzneb 3,191,926 WEB FQLDING AHARATUS Lawrence '1. Ramailra, Media, Pa., assignor to Avisun Corporation, Philadelphia, Pa., a corporation of Delaware Filed Feb. 6, 1963, Ser. No. 256,589 4 Claims. ((11. 270-86) The present invention relates to an improved .web folding apparatus.

Folding of a continuous web longitudinally upon itself is generally achieved by advancing such web into engagement with and relative to a triangular shaped former or folding plate. When employing such conventional apparatus for folding a transparent and glossy web, and particularly a web having relatively high slip characteristics, as for example in the case of a polyethylene or polypropylene film, the resulting folded web often exuibit-s scratches which detract from its optical properties and its usefulness as an article overwrap material. Accordingly, a primary object of the present invention is to provide a new or generally improved and more satisfactory web folding apparatus. 7

Another object is to provide an improved apparatus for folding continuous web-s longitudinally upon themselves at high speeds and Without scratching or otherwise marring the surfaces thereof.

Still another object is the provision of an improved web folding apparatus having means for maintaining a continuous traveling web in proper position as it is folded longitudinally upon itself.

A still further object is the provision of a web folding apparatus in which a layer of gas serves to maintain a Web separated from the folding apparatus While such web is being continuously advanced and folded upon itself.

In general, the apparatus for achieving the above and other related objects of the present invention includes an open V-shaped frame which serves to fold a web longitudinally upon itself as such web is advanced over the sides and across the corner of such frame; The frame is formed of tubing which is perforated for directing a gas under pressure, and preferably air, inbetween the frame and a Web which is advanced thereover. The frame perforations or openings direct the discharging streams of compressed gas perpendicularly against the traveling web so that the web is lifted slightly but not otherwise moved from its intended direction of travel. Additionally, it is essential that a number of openings be provided along the corner of the frame so that a plurality of streams of gas issue therefrom for keeping the web well spaced from the frame in this area.

The web to be folded may be led or guided to the folding frame by any suitable means, such as a pair of cooperating nip rolls or a conventional spreader roll. In the preferred embodiment the web to be folded is maintained registered with the fol-ding frame by means of streams of compressed gas which are impinged against the web as they issue from a perforated duct positioned oppositely of the frame corner and across or between the ends thereof. This perforated duct, together with the sides of the V-shaped frame, provide a structure of triangular configuration and may be formed, if desired, from a single piece of tubing. The perforations which extend from one end of the duct to a point almost at the center thereof comprise one group or series of perforations, while the perforations which extend from'the opposite end of the duct and also terminate short of the center thereof comprise a' second group or series. The erforations of such first group are inclined in a direction opposite to that of the second group so that the streams issuing from such two groups of perforations serve to smooth and automatically maintain the traveling web in proper position relative to the folding frame.

After leaving the frame, the folded web is advanced relative to at least one non-rotatable conduit, which permits the direction of web travel to be altered, and is then collected as in roll form. This non-rotatable conduit is also perforated for impinging a compressed gas against the folded web and thereby insure smooth and FIGURE 4 is a fragmentary view of a portion of the apparatus as viewed along the line IVIV of FIGURE 2. With reference to the drawing for a more detailed description, the apparatus of the present invention includes a base 15 formed of a plurality of interconnected channels 17, and a pair of upri hts 19 for. adjustably supporting a web folding frame 21 Channels 23, supported above the base 15 by uprights l? and columns 25, are provided with bearings 27 which rotatably support a shaft 29011 which is wound the continuous flat web 31 which is intended to be folded longitudinally upon itself.

The frame 21 is tack welded or otherwise fixed onto an open,- rigid, V-shaped plate 3% having blocks 35 and projecting studs 37. The studs 37 extend through aligned inclined slots 39 formed in the uprights 15 and are fixed in desired positions as by nuts 41. A strut 43 is pivotally connected to the plate 33 by a pin 45 and is adjustably fixed by nuts 47 to a trunnion d9 which is rotatably carried by a channel 51 fixed between the uprights 19. The threaded studs 3'7 and strut 43 together cooperate with the uprights 19 to maintain the plate '53, and the frame 21 carried thereon, in a desired angular position and may, of course, be adjusted to suit particular ope'rationg conditions.

The folding frame 21 is of V-shaped configuration and, as shown in FLJURES 2 and 4, is formed of tubing having perforations or openings at spaced intervals thereof. The tubing is shaped to provide arms or sides 53 and 55 which are connected together to provide a frame corner as indicated at 5'7. As heretofore indicated, the web 31 Which is to be folded may be led'to the folding frame by cooperating nip rolls or a conventional spreader roll. It is preferred, however, that the flat web 31 be passed over a perforated duct 59 and then across the frame corner 57 where it is folded longitudinally upon iselfn The folded web, indicated at 61, is advanced in-between non-rotatable conduits 63 which assist in changing its direction of travel and guide the same to a take-up shaft as which is carried by bearings 67 and rotated by suitable means, not shown.

The tubing forming the frame 21 and the duct 59 are both perforated to provide and maintain a cushioning or lubricating layer of gas, and preferably air, between such members and the web traveling thereover. Such layer of gasfacilitates rapid movement of the traveling web and, more important, insures that such movement is effected freely and without risk of scratching or otherwise damaging the web surfaces.

As best seen in FIGURE 2, the duct 59 is supported by the blocks 35 and is connected at one end to a suit- :able supply of gas under pressure, by a flexible hose 69. The opposite end of such tubing is closed so that the compressed gas delivered thereto is caused to discharge as fine streams through the spaced perforations or openings. The center perforation '71 in the duct 59 3 is located generally opposite to the corner 57 of the frame 21 and, as shown in FIGURE 3, has an axis which is substantially perpendicular to the tubing axis. However, the axes of the groups of perforations 73 and 75 on the opposite sides of such center perforation 71 are inclined in opposite directions relative to each other so that the streams of gas issuing therefrom extend along diverging planes. As such streams of gas impinge against the Web 31 traveling thereover, they tension and thus smooth the web in a transverse direction. More important, since in the present instance the groups of openings 73 and 75 are the same in size and number, the streams of compressed gas issuing therefrom serve to automatically position and maintain the web 31 centrally over such duct 59.

Compressed gas is also delivered by a flexible hose '77 into one end of the tubing forming arms or sides 53 and 55 of the frame 21. With the free end of the frame arm 55 being closed, the gas issues from perforations or openings '79 which extend substantially perpendiculary to the longitudinal axis of such tubing. As such streams of gas impinge against the traveling Web, they tend to lift the same slightly above the frame but do not otherwise change the path of the traveling web.

As best shown in FIGURE 4, the corner 57 of the frame 21 is provided with a plurality of perforations or openings 31 so that streams of gas issuing therefrom maintain the web 31 spaced from the frame throughout the web path as it travels across and relative to the frame corner 57.

The conduits 63, between which the folded web 61 travels after leaving the folding frame 21, are non-rotatably supported by suitable brackets 83 and are supplied with compressed gas, as by flexible hoses 85. The conduits 63 do not actually come into contact with the folded web as they alter its path of travel and guide the same to the take-up shaft 65. Instead, streams of compressed gas are discharged against the opposite sides of the folded web 61 through openings 87 in the conduits 63 so that again rapid movement of the folded web, without risk of web damage, is assured. While the use of a pair of conduits 63 is preferred since it offers good control over the traveling web, a single conduit 63 located between the folded web and the take-up shaft 65 will satisfactorily perform the functions as described above.

With the apparatus described above, web folding is effected rapidly and without risk of web damage. It will be understood that the size, spacing and number of openings provided in the frame arms or sides 53 and 55 and the duct 59, as well as the pressure of the compressed gas employed, may be varied as desired to suit particular operating conditions. Further, in lieu of the arrangement illustrated, the frame arms or sides 53 and 55 may be of unequal length so that the corner 57 effects folding of the Web 31 to one side of its center.

It is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A Web folding apparatus including a V-shaped frame 'having a pair of arms connected to each other at one end to form a corner of said frame, said frame being adapted to fold a web longitudinally upon itself as such web is advanced over said arms and across said corner, means for directing and maintaining a web registered with said frame as it is advanced thereover, said arms being formed of tubing, openings spaced along the length of each of said arms and extendin substantially perpendicular to the respective axis thereof, openings provided at spaced intervals along said corner, means for delivering compressed gas into said arms whereby a web passing over said arms and across the corner of said frame is maintained spaced therefrom by the gas as it is discharged through said openings, said frame being open in the area between said arms to permit the discharged gas to pass easily into the ambient atmosphere, means for collecting the folded web and means for directing the folded Web from said frame and to said collecting means.

2. Apparatus as defined in claim 1 wherein said means for directing and maintaining the web registered with said frame includes a perforated duct disposed oppositely from the frame corner and extending between the ends of said arms, perforations provided in said duct at spaced intervals thereof, the axis of one of said perforations being located generally opposite to the corner of the frame and extending substantially perpendicular to the axis of said duct, the axes of the perforations located on opposite sides of said one perforation extending outwardly along diverging planes, and means for delivering a compressed gas into said duct and through said perforations.

3. Apparatus as defined in claim 1 wherein said web directing means includes at least one non-rotatable conduit over which the folded web is passed for changing its direction of travel, said conduit being disposed across the path and at substantially right angles to the longitudinal axis of the folded web, openings provided at spaced intervals along the length of said conduit and directed toward the path of web movement, and means for delivering a compressed gas into said conduit and through the openings therein to maintain the folded web spaced therefrom.

4. A web folding apparatus incuding a V-shaped frame having a pair of arms connected to each other at one end to form a corner of said frame, said frame being adapted to fold a web longitudinally upon itself as such web is advanced over said arms and across said corner, a duct disposed oppositely of said frame corner and extending between the ends of said arms, said duct having one perforation positioned generally opposite of said frame corner and extending substantially perpendicularly to the duct axis, a group of spaced perforations provided in said duct on each of the opposite sides of said one perforation, the perforations in the respective groups of perforations extending in the same direction and in diverging relationship with respect to said one perforation, said arms being formed of tubing, openings spaced along the length of each of said arms, openings provided at spaced intervals along said corner, means for delivering compressed gas into said duct and said arms whereby the gas issuing from the duct perforations maintains a web registered with said frame as it passes thereover While the gas discharged through said openings serves to maintain such web spaced from the arms and corner of said frame, said frame being open in the area between said arms and duct to permit the discharged gas to pass easily into the ambient atmosphere, means for collecting the folded web and means for directing the folded web from said frame and to said collecting means.

References Cited by the Examiner UNITED STATES PATENTS EUGENE R. CAPOZIO, Primary Examiner. 

1. A WEB FOLDING APPARATUS INCLUDING A V-SHAPED FRAME HAVING A PAIR OF ARMS CONNECTED TO EACH OTHER AT ONE END TO FORM A CORNER OF SAID FRAME, SAID FRAME BEING ADAPTED TO FOLD A WEB LONGITUDINALLY UPON ITSELF AS SUCH WEB IS ADVANCED OVER SAID ARMS AND ACROSS SAID CORNER MEANS FOR DIRECTING AND MAINTAINING A WEB REGISTERED WITH SAID FRAME AS IT IS ADVANCED THEREOVER, SAID ARMS BEING FORMED OF TUBING, OPENINGS SPACED ALONG THE LENGTH OF EACH OF SAID ARMS AND EXTENDING SUBSTANTIALLY PERPENDICULAR TO THE RESPECTIVE AXIS THEREOF, OPENINGS PROVIDED AT SPACED INTERVALS ALONG SAID CORNER, MEANS FOR DELIVERING COMPRESSED GAS INTO SAID ARMS WHEREBY A WEB PASSING OVER SAID ARMS AND ACROSS THE CORNER OF SAID FRAME IS MAINTAINED SPACED THEREFROM BY THE GAS AS IT IS DISCHARGED THROUGH SAID OPENINGS, SAID FRAME BEING OPEN IN THE AREA BETWEEN SAID ARMS TO PERMIT THE DISCHARGED GAS TO PASS EASILY INTO THE AMBIENT ATMOSPHERE, MEANS FOR COLLECTING THE FOLDED WEB AND MEANS FOR DIRECTING THE FOLDED WEB FROM AND SAID FRAME AND TO SAID COLLECTING MEANS. 